Lifting device

ABSTRACT

A lifting device includes a lifting toe adapted to engage under an article to be lifted by the device, a top abutment adapted to engage with a top surface of the article, an actuating screw jack adapted to move said lifting toe and said top abutment towards one another and into gripping relationship with the article, and slotted grid plates presenting a plurality of recessed attachment positions one to which is located substantially over the center of gravity of the article. Where the lifting device is to be used for lifting cast concrete panels, an insert for the lower edge of the panel is used during casting of the panel to provide the panel with a recess adapted to receive said lifting toe.

United States Patent Carroll [45] Oct. 10, 1972 [541' LIFTING DEVICE3,076,674 2/1963 Anderson ..294/1o3 [72] Inventor: Ronald Frank Cam",Heme, 3,244,446 4/1966 Bopp ..294/67.l A Hempstead, England 3,275,3679/1966 Bopp ..294/67.l A

[73] Assignee: National Research Development Corporation, London,England [22] Filed: Nov. 18, 1969 [21] Appl. No.: 877,839

[52] US. Cl ..294/103, 294/112, 294/67 AA, v 249/51 [5 1] Int. Cl...B66c l/00 [58] Field of Search....294/l03, 63; 249/67.l A, 112,

[56] References Cited UNITED STATES PATENTS 2,535,911 12/1950 Frame..294/103 2,886,371 5/1959 Smock ..294/103 X 3,339,966 9/1967 Carlson..294/112 X 3,066,968 12/1962 Brooks ..294/63 Primary Examiner-Even C.Blunk Assistant Examiner-Merle F. Maffei Att0meyCushman, Darby andCushman ABSTRACT A lifting device includes a lifting toe adapted toengage under an article to be lifted by the device, a top abutmentadapted to engage with a top surface of the article, an actuating screwjack adapted to move said lifting toe and said top abutment towards oneanother and into gn'pping relationship with the article, and slottedgrid plates presenting a plurality of recessed attachment positions oneto which is located substantially over the center of gravity of thearticle. Where the lifting device is to be used for lifting castconcrete panels, an insert for the lower edge of the panel is usedduring casting of the panel to provide the panel with a recess adaptedto receive said lifting toe.

6 Claims, 9 Drawing Figures PATENTEDH T 10 me 3; 697; 1 1s SHEET 2 0F 7FIG-.2.

PNENTEDnm 10 I972 SHEET 3 [IF 7 PATENTEDncI 10 I972 k EQM wE mm a @QwtLIFTING DEVICE The invention relates to lifting devices and inparticular to lifting devices for L-shaped panels e.g. of concrete.

According to the present invention, a lifting device includes a liftingtoe adapted to engage under an article to be lifted by the device, a topabutment adapted to engage with a top surface of the article, actuatingmeans adapted to move said lifting toe and said top abutment towards oneanother and into gripping relationship with the article, and attachmentmeans adapted to present a plurality of attachment positions one ofwhich is located substantially over the center of gravity of thearticle.

Where the lifting device is to be used for lifting cast concrete panels,the invention also includes a lifting assembly comprising the device ofthe present invention and insert means adapted to serve as an insert forthe lower edge of the panel during casting of the panel thereby toprovide the panel with a recess adapted to receive said lifting toe.

In order that the invention may be more fully understood, an embodimentthereof will now be described, by way of example, with reference to theaccompanying drawings of which:

FIG. 1 shows an inside view of a mould incorporating an insert means asabove referred to;

FIGS. 2 and 3 show details of the insert block and the block withdrawalmeans;

FIGS. 4(L) and 4(R) represent left and right portions, respectively,which join together to form a large scale view of a longitudinal sectionof the lifting device and the article to be lifted turned anti-clockwisethrough 90; 1

FIGS. 5(L) and 5(R) represent left and right portions, respectively,which join together to form a large scale view of a side elevation ofthe device and part of the associated lifting tackle; and

FIGS. 6(L) and 6(R) represent left and right portions, respectively,which join together to form a large scale view of a face view of thedevice showing a preferred form of abutment means.

Thus referring to the drawings, the device 10 comprises a leg part 12connected with a frame 14 by a screw jack actuating means 16 controllingthe separation of a lifting toe 18 on the lower end of the leg 12 andholding gates 20 at the upper end of the frame 16. Profiled grid plates22 mounted at the top end of the frame 16 provide an attachment meanspresenting five attachment positions 24 to 29 for the lifting link 32 ofa lifting tackle 34. The link 32 is fitted with a handle 33 whereby theposition of this link may be varied at will by an operator holding theother end of the handle.

In more detail, the frame 16 comprises a head 36 from which extend twoarms 38 located one on each side of the leg 12. Each arm 38 comprises anA-frame strengthened by stiffening plates 40 and struts 42. The two armsare interconnected by transverse struts 44 and a steel pad 46 which isadapted to abut with the face of the article (48) to be lifted.

At its lower end, the leg 12 is perforated by a row of holes 49 and alocking pin 50 for insertion through holes 49 is secured to the frame 16by a length of chain 51. The adjacent end portions of the A-frames alsocarry guide plates 52 for the leg 12. In their middle portions the sideelements are perforated by longitudinal guide slots 53, these perforatedportions being strengthened by correspondingly slotted reinforcementplates 54. At their upper portions, the inner side elements carry tworows of aligned bushes 56. The outer side elements of the A-frames atthis portion carry protective tubing 58 adapted to protect the deviceagainst knocks during use.

The upper ends of the A-frame sides are joined together by a steel plate60 carrying a second abutment pad 62. A hollow square section beam 64 issecured to the plate 60 above the pad 62 and this provides a guide forthe square section axles 66 of the laterally spaced holding gates 20whereby the spacing apart of these gates can be altered if necessary tosuit the article to be lifted. Abutment pads 70, 72 are also provided onthose surfaces of the gates 20 and beam 64 which will engage with thearticle to be lifted.

The grid plates 22 are secured rigidly to the remainder of the frame 14as will be clear from the drawings. The plates 22 extend on both sidesof that part of the article 48 gripped by the device 10 and provideattachment positions24 to 29 on these two sides. This allows the liftinglink 32 of lifting tackle 34 to be engaged over the center of gravity ofthe article 48 by a suitable choice of the attachment position in whichthis link is to be located. As shown in the drawings, the lifting tackleincludes a shock absorber 74 and and eye 76 for engagement by aconventional lifting crane or gantry.

The leg 12 of the device is provided with a handle 77 at its lower endand at its upper end the leg is pivotally connected by pivots 78 withthe female part 79 of the screw jack 16. As shown in the drawings thepivots 78 are free to slide in the slots 53 and enlarged ends 80 of thepivots prevent their accidental escape from these slots.

The male part 81 of the jack 16 is mounted for rotation in a casing part82 of the leg 12 and carries a bevel gear 84. This meshes with acorresponding gear 86 carried on the inner end of an actuating spindle88 which is knurled at its outer end 90.

At its upper end, the casing 82 is connected by a collared eyebolt 92with a link 94 secured to the frame 14 by a bolted pivot pin 95 passingthrough one pair of opposed bushes 56, the choice of bushes depending onthe desired length of the device in view of the article to be lifted.

In operation of the device above described, the device 10 is suspendedfrom the appropriate attachment position on the plates 22 and is movedtowards the article to be lifted until the pads 46, 62 abut, or nearlyso, with the adjacent face of the article. During this movement, thelifting toe is held back from this face by the locking pin 50 which islocated in one of the holes 49. The length of the device will have beenpreset with the eyebolt 92 as above described.

The operator now returns the locking pin 50 to an appropriate storageplace in the frame 14 and using handle 77 he pushes the lifting toe 18under the article to be lifted. The actuating spindle 88 is next rotatedto operate the screw jack 16 and bring the lifting toe l8 and holdinggates 20 into gripping relationship with the article. The lifting tackle34 is then operated to move the article to some predetermined locationand the reverse procedure to that above described is carried out to freethe device from the article so that the device can be removed from thelocation, using lifting tackle 34, for further use.

It will be noted that the upper surface of the lifting toe 18 isspecially profiled and in accordance with a preferred feature of theinvention, the article 48 at its lower end provides the lifting toe 18with a profiled recess matching the profile of toe 18. Thus inaccordance with another aspect of the invention, there is provided amould insert 100 comprising a block of which the upper part 102 isconnected to the lower part 104 of the block by keyway 106. Asillustrated in FIG. 1 of the drawings, this block may be mounted on thelonger baseboard 108 for a mould space 22 before the associated mouldmember 110 is mounted in a battery and filled with concrete mix. Theco-pending US. Patent application filed on the same date as the presentapplication under the title Battery Casting of Concrete Panels andnaming Mr. Cross as inventor discloses a casting process in which thisblock may be incorporated to provide an article with the desired liftingslot.

As will be seen from FIGS. 2 and 3, the front face 108 of the top part102 of the block has a threaded bore 112 into which the screw part 113of a withdrawal mechanism 114 may be screwed when the cast panel isexposed after curing. The block 100 tapers from the front facerearwardly to allow easy withdrawal of the top part 102 using withdrawalmechanism 114. The upper face of top part 110 is V-shaped when viewedfrom the side, the two faces of the V being inclined at 8 to thehorizontal. The lower face of top part 110 inclines at 15 to horizontal.

The withdrawal mechanism 114 comprises a base part 116 which in theoperative position of the mechanism is spaced from the adjacent face ofthe article by arms 118. In operation, the control knob 122 is firstrotated to lock the screw 113 in the threaded bore 112 and thereafterrotation is by a suitable key fitted on to the square section end 124 ofthe screw part 1 13.

Once removed from the cast panel, the top part 110 leaves a recessmatching the lifting toe 18 in profile. The toe may therefore beinserted in this recess and the actuating spindle 88 is rotated to givethe device a firm grip on the panel 48 prior to removal from the mouldmember 110 in the manner above described.

I claim:

1. A lifting device for gripping top and bottom surfaces of an articleto be lifted, comprising a frame means,

a lifting toe carried by the frame means for engaging an under surfaceof an article to be lifted, said lifting toe being associated with anend part of a leg member which is pivotally mounted relative to theframe means so that the lifting toe can be pivoted into and out ofoperative and inoperative positions in which the lifting toe isrespectively in a position to engage an article to be lifted or in aposition to be held clear of an article while the device is brought intoposition for a lifting operation,

means for moving the lifting toe between said operative and inoperativepositions,

a top abutment means for engaging an upper surface of an article to belifted,

actuating means for moving said lifting toe and said top abutment meanstowards one another and into gripping relationship with an article, saidactuating means being operatively associated with an adjustable meanscarried by said device, and said adjustable means being interconnectedbetween an upper portion of the device and a part of said leg member sothat operation of the adjustable means changes the effective length ofthe device by moving said leg member towards or away from an upper partof said device,

means for securing said adjustable means at different locations on saidupper portion of the device so as to adjust the effective length of thedevice, and

attachment means connected to the device for presenting a plurality ofattachment positions for lifting the device, one of which positions islocated substantially over the center of gravity of an article carriedby the device.

2. A lifting device for gripping top and bottom surfaces of an articleto be lifted, comprising a frame means,

a lifting toe carried by the frame means for engaging an under surfaceof an article to be lifted, said lifting toe being associated with anend part of a leg member which is pivotally mounted on a central part ofthe leg member so that the lifting toe can be pivoted into and out ofoperative and inoperative positions in which the lifting toe isrespectively in a position to engage an article to be lifted or in aposition to be held clear of an article while the device is brought intoposition for a lifting operation,

means for moving the lifting toe, relative to the remainder of thedevice, between said operative and inoperative positions,

a top abutment means for engaging an upper surface of an article to belifted,

actuating means for moving said lifting toe and said top abutment meanstowards one another and into gripping relationship with an article, saidactuating means being operatively associated with a screw jack meanscarried by said device, said central part of said leg member comprisingone element of said screw jack means and said actuating means beingadapted to operate another element of the screw jack means so thatoperation of the screw jack changes the effective length of the deviceby moving said leg member towards or away from an upper part of saiddevice, said actuating means further comprising a spindle carrying abevel gear which meshes with a corresponding gear on said other elementof the screw jack means, and said other element being mounted forrotation in a casing part of the leg,

means for securing said casing part at different locations on said upperportion of the device so as to adjust the effective length of thedevice, and

attachment means connected to the device for presenting a plurality ofattachment positions for lifting the device, one of which positions islocated substantially over the center of gravity of an article carriedby the device.

3. The lifting device of claim 2, and including a body portion locatedbetween said lifting toe and said top abutment, and wherein saidattachment means includes a first portion defining attachment positionsto one side of said body portion and a second portion definingattachment positions to the other side of said body portion.

4; A device as claimed in claim 2 wherein the attachment means comprisesgrid plates presenting a lifting slot, and said attachment positions areprovided by recesses spaced along the top edge of the slot.

5. A device as claimed in claim 2 wherein the top abutment comprisesholding gates, and spacer means are provided for altering the separationof the gates.

6. A lifting device for gripping top and bottom surfaces of an articleto be lifted, comprising a frame means,

a lifting toe carried by the frame means for engaging an under surfaceof an article to be lifted, said lifting toe being associated with anend part of a leg member which is pivotally mounted relative to theframe means so that the lifting toe can be pivoted into and out ofoperativeand inoperative positions in which the lifting toe isrespectively in a position to engage an article to be lifted or in aposition to be held clear of an article while the device is brought intoposition for a lifting operation,

means for moving the lifting toe between said operative and inoperativepositions,

a top abutment means for engaging an upper surface of an article to belifted,

actuating means for moving said lifting toe and said top abutment meanstowards one another and into gripping relationship with an article, saidactuating means being operatively associated with a screw jack meanscarried by said device, and said screw jack means being interconnectedbetween an upper portion of the device and a part of said leg member sothat operation of the screw jack changes the effective length of thedevice by moving said leg member towards or away from an upper part ofsaid device,

means for securing said screw jack means at different locations on saidupper portion of the device so as to adjust the effective length of thedevice, and

attachment means connected to the device for presenting a plurality ofattachment positions for lifting the device, one of which positions islocated substantially over the center of gravity of an article carriedby the device.

1. A lifting device for gripping top and bottom surfaces of an articleto be lifted, comprising a frame means, a lifting toe carried by theframe means for engaging an under surface of an article to be lifted,said lifting toe being associated with an end part of a leg member whichis pivotally mounted relative to the frame means so that the lifting toecan be pivoted into and out of operative and inoperative positions inwhich the lifting toe is respectively in a position to engage an articleto be lifted or in a position to be held clear of an article while thedevice is brought into position for a lifting operation, means formoving the lifting toe between said operative and inoperative positions,a top abutment means for engaging an upper surface of an article to belifted, actuating means for moving said lifting toe and said topabutment means towards one another and into gripping relationship withan article, said actuating means being operatively associated with anadjustable means carried by said device, and said adjustable means beinginterconnected between an upper portion of the device and a part of saidleg member so that operation of the adjustable means changes theeffective length of the device by moving said leg member towards or awayfrom an upper part of said device, means for securing said adjustablemeans at different locations on said upper portion of the device so asto adjust the effective length of the device, and attachment meansconnected to the device for presenting a plurality of attachmentpositions for lifting the device, one of which positions is Locatedsubstantially over the center of gravity of an article carried by thedevice.
 2. A lifting device for gripping top and bottom surfaces of anarticle to be lifted, comprising a frame means, a lifting toe carried bythe frame means for engaging an under surface of an article to belifted, said lifting toe being associated with an end part of a legmember which is pivotally mounted on a central part of the leg member sothat the lifting toe can be pivoted into and out of operative andinoperative positions in which the lifting toe is respectively in aposition to engage an article to be lifted or in a position to be heldclear of an article while the device is brought into position for alifting operation, means for moving the lifting toe, relative to theremainder of the device, between said operative and inoperativepositions, a top abutment means for engaging an upper surface of anarticle to be lifted, actuating means for moving said lifting toe andsaid top abutment means towards one another and into grippingrelationship with an article, said actuating means being operativelyassociated with a screw jack means carried by said device, said centralpart of said leg member comprising one element of said screw jack meansand said actuating means being adapted to operate another element of thescrew jack means so that operation of the screw jack changes theeffective length of the device by moving said leg member towards or awayfrom an upper part of said device, said actuating means furthercomprising a spindle carrying a bevel gear which meshes with acorresponding gear on said other element of the screw jack means, andsaid other element being mounted for rotation in a casing part of theleg, means for securing said casing part at different locations on saidupper portion of the device so as to adjust the effective length of thedevice, and attachment means connected to the device for presenting aplurality of attachment positions for lifting the device, one of whichpositions is located substantially over the center of gravity of anarticle carried by the device.
 3. The lifting device of claim 2, andincluding a body portion located between said lifting toe and said topabutment, and wherein said attachment means includes a first portiondefining attachment positions to one side of said body portion and asecond portion defining attachment positions to the other side of saidbody portion.
 4. A device as claimed in claim 2 wherein the attachmentmeans comprises grid plates presenting a lifting slot, and saidattachment positions are provided by recesses spaced along the top edgeof the slot.
 5. A device as claimed in claim 2 wherein the top abutmentcomprises holding gates, and spacer means are provided for altering theseparation of the gates.
 6. A lifting device for gripping top and bottomsurfaces of an article to be lifted, comprising a frame means, a liftingtoe carried by the frame means for engaging an under surface of anarticle to be lifted, said lifting toe being associated with an end partof a leg member which is pivotally mounted relative to the frame meansso that the lifting toe can be pivoted into and out of operative andinoperative positions in which the lifting toe is respectively in aposition to engage an article to be lifted or in a position to be heldclear of an article while the device is brought into position for alifting operation, means for moving the lifting toe between saidoperative and inoperative positions, a top abutment means for engagingan upper surface of an article to be lifted, actuating means for movingsaid lifting toe and said top abutment means towards one another andinto gripping relationship with an article, said actuating means beingoperatively associated with a screw jack means carried by said device,and said screw jack means being interconnected between an upper portionof the device and a part of said leg member so that operation of thescrew jack changeS the effective length of the device by moving said legmember towards or away from an upper part of said device, means forsecuring said screw jack means at different locations on said upperportion of the device so as to adjust the effective length of thedevice, and attachment means connected to the device for presenting aplurality of attachment positions for lifting the device, one of whichpositions is located substantially over the center of gravity of anarticle carried by the device.